These Nokya Heavy Duty Headlight High Beam H9 Wire Harnesses have been designed to be plugged into your Mazda 6's stock wiring. Aftermarket bulbs or not, your Mazda 6 stock lighting H9 harnesses are not designed to handle extended periods of use, or operation in adverse or severe conditions. To address this, Nokya offers these H9 Heavy Duty Headlight High Beam harnesses as a cheap and relatively easy upgrade to your stock Mazda 6 electrical system. They work as replacements for damaged stock H9 harness plugs, or as complete upgrades as a precautionary measure against harness plug burnouts (which can permanently damage your Mazda 6 headlight housings). These Mazda 6 Heavy Duty Headlight High Beam H9 Wire Harnesses also help to handle the increased demands of aftermarket Headlight High Beam bulbs, Nokya brand or otherwise. Each set consists of 2 harnesses.